Preferred Language
Articles
/
jbcd-131
Effect of surface treatments and thermocycling on shear bond strength of various artificial teeth with different denture base materials
...Show More Authors

Background: Separation and deboning of artificial teeth from denture bases present a major clinical and labortory problem which affect both the patient and the dentist. The optimal bond strength of artificial teeth with denture base reinforced with nanofillers and flexible denture bases and the effect of thermo cycling should be evaluated. This study was conducted to evaluate and compare the shear bond strength of artificial teeth (acrylic and porcelain) with denture bases reinforced by 5% Zirconium oxide nanofillers and flexible bases under the effect of different surface treatments and thermo cycling and comparing the results with conventional water bath cured denture bases. Material and methods: Two types of artificial teeth; acrylic and porcelain were used and prepared for this study. Five specimens of each tooth type were processed to each denture base materials after the application of different surface treatments; these teeth were bonded to heat polymerized, nano composite resin and flexible denture bases. Specimens were thermo cycled and tested for bond strength until fracture with an Instron universal testing machine. Data were analyzed with analysis of variance and student T-test. Photomicrographic examinations were used to identify adhesive and cohesive failures within debonded specimens. Results: The mean force required to fracture the specimens were obviously larger for nanocomposite specimens compared with the heat cured and flexible specimens. The most common failure was cohesive within the tooth or the denture base. With each base material, the artificial teeth which were treated with thinner exhibited highest shear bond strength. Thermocycling had deleterious effect on the flexible denture base specimens. In general, nanocomposite and heat cured groups failed cohesively within the artificial tooth. While the valplastic groups failed adhesively at the tooth denture base interface. Conclusions: Within the limitations of this study, the type of denture base materials and surface treatments of the tooth selected for use may influence the shear bond strength of the tooth to the base. Selection of more compatible combinations of base and artificial teeth may reduce the number of prosthesis fractures and resultant repairs. Key words: acrylic teeth, porcelain teeth, Nano composite denture base, thermo cycling, flexible denture, thinner,

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 20 2022
Journal Name
International Journal Of Emerging Technologies In Learning (ijet)
Impact of a Proposed Strategy According to Luria’s Model in Realistic Thinking and Achievement in Mathematics
...Show More Authors

The research aims to find the impact of a proposed strategy according to the Luria model on realistic thinking among fifth-class scientific students and their achievement in mathematics. To achieve it, the experimental research method and the quasi-experimental design were used for two equal groups, one of them is a control group taught in traditional way and the other is an experimental one taught according to strategy based on Luria model. The research community represents the students of the fifth scientific class from the General Directorate of Education of Karkh First. The research sample (40) students were deliberately chosen and distributed equally between the two groups after making sure that they were equals in their previo

... Show More
View Publication
Scopus (16)
Scopus Crossref
Publication Date
Sun Mar 30 2003
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Catalytic Pour Point Reduction and Viscosity Improvement of Lubricating Oil Fractions using Sulfided Nickel-Tungsten Catalysts
...Show More Authors

View Publication Preview PDF
Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Analysis of Temperature and Residual Stress Distribution in CO2 Laser Welded Aluminum 6061 Plates Using FEM
...Show More Authors

This paper develops a nonlinear transient three-dimensional heat transfer finite element model and a rate independent three-dimensional deformation model, developed for the CO2 laser welding simulations in Al-6061-T6 alloy. Simulations are performed using an indirect coupled thermal-structural method for the process of welding. Temperature-dependent thermal properties of Al-6061-T6, effect of latent heat of fusion, and the convective and radiative boundary conditions are included in the model. The heat input to the model is assumed to be a Gaussian heat source. The finite element code ANSYS12, along with a few FORTRAN subroutines, are employed to obtain the numerical results. The benefit of the proposed methodology is that it

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Comparative sensitivity of two freshwater snail Melanopsis nodosa and Bulinus truncatus to 2, 4-D pesticide
...Show More Authors

The molluscicidal effects of herbicide 2, 4-D were studied against tow species of freshwater snail Bulinus truncatus and Melanopsis nodosa by short term experiments. Calculated values of lethal concentrations (LC50 and LC100) were maid to two spices for different period of time 24hr, 48hr, 72hr and 96hr. The study had showed that the herbicide 2, 4-D was toxic against the tow species. The toxicity of the herbicide was low or unknown in low concentrations in the first period of exposure 24and 48hr to two spices but it increase gradually with increase period of exposure. The spice of B.truncatus was more tolerant than the M.nodosa. All the individual of M nodosa was death while in B.truncatus the complete death was not appear until finish the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 28 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Evaluation of the Construction, Build, Operate and Transfer (B.O.T): Applied Research in Southern Cement State Company
...Show More Authors

   Form of investment in infrastructure important factor to drive economic growth in any country, with the dwindling ability of governments to provide the necessary funds for such investments, emerged as a rising trend for private sector involvement in public projects and infrastructure, and one of these trends is the build-operate-transfer system (BOT), which commonly used in various developed and developing countries as one of the tools used in the implementation of these investments, as the private sector under this system design, finance, build and operate the project, and are re-administration of the state after a certain period under a contractual agreement between the parties of the contract. As this system provides majo

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 27 2024
Journal Name
International Journal Of Design & Nature And Ecodynamics
Amino Acid and Hormonal Profiling of the Adrenal Gland in the Pin-Tailed Sandgrouse (Pterocles alchata)
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
The Energy Spectra and Heat Capacity of GaAs Gaussian Quantum Dot in an External Magnetic Field
...Show More Authors

In this paper, a theoretical study of the energy spectra and the heat capacity of one electron quantum dot with Gaussian Confinement in an external magnetic field are presented. Using the exact diagonalization technique, the Hamiltonian of the Gaussian Quantum Dot (GQD) including the electron spin is solved. All the elements in the energy matrix are found in closed form. The eigenenergies of the electron were displayed as a function of magnetic field, Gaussian confinement potential depth and quantum dot size. Explanations to the behavior of the quantum dot heat capacity curve, as a function of external applied magnetic field and temperature, are presented.

View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Thu Jan 01 2015
Journal Name
Aaa
Green Synthesis of Silver Nanoparticles by Kumquat (Fortunella Margaarita) Fruit Extract and Efficacy the Antimicrobial Activity
...Show More Authors

View Publication Preview PDF
Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Evaluation of Seepage Force and Overall Stability Factor Along Proposed Baghdad Metro Tunnel Across Tigris River
...Show More Authors

Baghdad Metro is a vital project to fulfill the rapidly increased traffic volume requirements. The proposed metro will connect both sides of Baghdad City, passing under the Tigris River. This study is employed finite elements software (PLAXIS 3D) to evaluate the seepage force developed around the sub-river segment during different construction stages and for other water levels of Tigris. The study found that when the water level changes from maximum to minimum, the developed seepage force decreases by (8 to 13%) and (22 to 27%) respectively. The seepage forces were found to be maximum during the excavation stage. The concrete lining process led to a noticeable reduction in seepage forces at all locations. The study also

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Baghdad Science Journal
Determination of Sulfacetamide Sodium in Pure and Their Pharmaceutical Formulations by Using Cloud Point Extraction Method
...Show More Authors

      In this study, simple, low cost, precise and speed spectrophotometric methods development for evaluation of sulfacetamide sodium are described. The primary approach contains conversion of sulfacetamide sodium to diazonium salt followed by a reaction with p-cresol as a reagent in the alkaline media.  The colored product has an orange colour with absorbance at λmax 450 nm. At the concentration range of (5.0-100 µg.mL-1), the Beer̆ s Low is obeyed with correlation coefficient (R2= 0.9996), limit of detection as 0.2142 µg.mL-1, limit of quantification as 0.707 µg.mL-1 and molar absorptivity as 1488.249 L.mol-1.cm-1. The other approach, cloud point extraction w

... Show More
View Publication Preview PDF
Scopus (7)
Scopus Clarivate Crossref